HCPCS Level II modifier
Modifier XU
Modifier XU is a HCPCS Level II modifier. CMS describes it as: Unusual non-overlapping service, the use of a service that is distinct because it does not overlap usual components of the main service.
Source: CMS HCPCS Level II, October 2026 file dated September 23, 2026. Publisher page
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- Modifier
- XU
- Type
- HCPCS Level II modifier, maintained by CMS
- CMS description
- Unusual non-overlapping service, the use of a service that is distinct because it does not overlap usual components of the main service
- Claim form
- CMS-1500 item 24D, up to four modifiers per line. 837P SV101-3 to SV101-6.
- Guidance
- CMS HCPCS quarterly update
Distinct and repeat services
- 59Distinct procedural service
- XESeparate encounter, a service that is distinct because it occurred during a separate encounter
- XPSeparate practitioner, a service that is distinct because it was performed by a different practitioner
- XSSeparate structure, a service that is distinct because it was performed on a separate organ/structure
- 76Repeat procedure by the same physician
- 77Repeat procedure by another physician
- 91Repeat clinical diagnostic lab test
Related modifiers
- 59Distinct procedural service
- XESeparate encounter, a service that is distinct because it occurred during a separate encounter
- XPSeparate practitioner, a service that is distinct because it was performed by a different practitioner
- XSSeparate structure, a service that is distinct because it was performed on a separate organ/structure
- 76Repeat procedure by the same physician
- 77Repeat procedure by another physician
- 91Repeat clinical diagnostic lab test
- ZANovartis/sandoz
Related pages
- All CPT and HCPCS modifiersA to Z list
- CMS-1500 claim formModifiers go in item 24D
- Denial code CO-4Modifier missing or does not fit the code
- Denial code CO-182Modifier invalid on the date of service
- Denial code CO-97Included in another service
- Denial code CO-236Procedure or modifier pair not compatible
- HCPCS Level II code lookup
- Denial and remark codes
Questions
What does modifier XU mean?
Modifier XU is a HCPCS Level II modifier. CMS describes it as: Unusual non-overlapping service, the use of a service that is distinct because it does not overlap usual components of the main service.
Is modifier XU a CPT or a HCPCS modifier?
XU is a HCPCS Level II modifier from the CMS quarterly HCPCS file. Two-digit numeric modifiers, such as 25 or 59, are CPT modifiers.
Where does modifier XU go on a claim?
On the CMS-1500 it goes in item 24D next to the procedure code. Each line holds up to four modifiers. On an 837P it goes in SV101-3 to SV101-6.
What denial comes back when a modifier is wrong?
A missing or mismatched modifier often comes back as CARC 4. A modifier that was not valid on the date of service comes back as CARC 182. A bundling edit the modifier should have bypassed comes back as CARC 97 or 236.